Cargo bed support assembly for a truck

ABSTRACT

A cargo bed assembly for a pickup truck includes an aluminum truck bed above a pair of frame rails. A plurality of roll-formed 6000-series aluminum cross-members extend along a width of the truck bed and contact the underside of the truck bed. The cross-members include longitudinal channels. Each cross-member contacts a pair of extruded 6000-series aluminum spacers underneath the cross-member at spaced locations to align with the frame rails. The spacers contact the frame rails and at least partially surround a portion of the outer surface of the cross-members to separate the cross-members from the frame rails.

TECHNICAL FIELD

The present disclosure relates to a support assembly for a cargo bed ofa truck. More specifically, the present disclosure relates to anextruded aluminum reinforcement member secured with an aluminumcross-member that together support the underside of a pickup truck bed.

BACKGROUND

Pickup trucks are motor vehicles with a rear open top cargo area that isoften referred to as a bed. Pickup trucks are popular largely becausethe bed allows the vehicle to be utilized in many different ways,including carrying a variety of types of cargo and towing various typesof trailers. Traditionally, the majority of body structures on pickuptrucks have been formed from steel alloys. Through years of experience,pickup truck designers have learned how to design steel truck body partsthat withstand the variety of demanding pickup truck applications. Thecurrent regulatory and economic environment have increased theimportance of making pickup trucks more fuel efficient while maintainingor improving functionality and durability. One way to reduce the fuelconsumption of a vehicle, especially when unloaded, is to reduce vehiclestructure weight.

Aluminum alloys typically have a higher strength to weight ratio thansteel alloys. Consequently, replacing steel with aluminum offers thepotential for weight reduction. However, the elastic modulus of aluminumis generally lower than the elastic modulus of steel. Additionally,fabrication techniques and methods of joining parts that work well forsteel parts may not work well for the same aluminum part. Due to theseand other differences, simple material substitution does not necessarilyproduce an acceptable design.

Aluminum alloys are generally identified by a four-digit number, thefirst digit of which typically identifies the major alloying element.When describing a series of aluminum alloys based on the major alloyingelement, the first number may be followed by three x's (upper or lowercase) or three zeros. For example, the major alloying element in 6xxx(or 6000) series aluminum alloy is magnesium and silicon, while themajor alloying element of 5xxx series is magnesium and for 7xxx seriesis zinc. Additional numbers represented by the letter ‘x’ (or zeros) inthe series designation define the exact aluminum alloy. For example, a6061 aluminum alloy has a composition of 0.4-0.8% Silicon, 0-0.7% Iron,0.15-0.4% Copper, 0-0.15% Manganese, 0.8-1.2% Magnesium, 0.04-0.35%Chromium, 0-0.25% Zinc, and 0-0.15% Titanium. Different alloys providedifferent trade-offs of strength, hardness, workability, and otherproperties.

In addition, five basic temper designations may be used for aluminumalloys which are: F—as fabricated, O—annealed, H—strain hardened,T—thermally treated, and W—as quenched (between solution heat treatmentand artificial or natural aging). The temper designation may be followedby a single or double digit number for further delineation. For example,aluminum with a T6 temper designation has been solution heat treated andartificially aged, but not cold worked after the solution heat treatment(or such that cold working would not be recognizable in the materialproperties).

SUMMARY

According to one embodiment, a vehicle comprises a 6000-series aluminumtruck bed having a width, a top surface and a bottom surface. A6000-series aluminum cross-member is mounted to the bottom surface ofthe truck bed and extends along the width of the truck bed.

The vehicle may also include an extruded 6000-series aluminumreinforcement member attached to an underside of the cross member,wherein the reinforcement member includes a base secured between a framerail and the cross-member.

The reinforcement member may be generally “U” shaped with a pair ofsidewalls extending from the base. The cross-member may also havesidewalls extending from a base to define a channel, and flangesextending from the sidewalls away from the channel. The reinforcementmember can be positioned outside of the channel with its sidewalls andbase contacting the respective sidewalls and base of the cross-member.

In another embodiment, a cargo bed assembly for a truck includes a bed,a cross-member, and a reinforcement member. The bed is a substantiallyflat aluminum bed. The cross-member is aluminum and has a base and apair of sidewalls extending from opposing sides of the base. Thecross-member is mounted to an underside of the bed. The reinforcementmember is in contact with the base and at least a portion of thesidewalls, and is disposed between the cross-member and a frame rail ofthe truck.

In yet another embodiment, a method of manufacturing a reinforcementassembly for a truck bed includes roll forming an aluminum sheet to forma cross-member having a base, a pair of opposing side walls extendingfrom the base, and a pair of flanges each extending from one of thesidewalls and substantially parallel with the base. Aluminum is extrudedto provide an extruded aluminum reinforcement member. The method thenincludes attaching the reinforcement member to the cross-member to spacethe cross-member from a frame rail of the truck.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a pickup truck having a truck bedaccording to one embodiment of the present disclosure.

FIG. 2 is a bottom plan view of the truck bed with a plurality ofreinforcement assemblies attached thereto according to one embodiment.

FIG. 3 is a perspective view of a cross-member and a pair ofreinforcement members of the reinforcement assembly for securing to thebottom surface of the truck bed according to one embodiment.

FIG. 4 is a cross-section taken along line 3-3 of the reinforcementassembly of FIG. 3.

FIG. 5 is a side perspective view of the reinforcement assembly securedunder the truck bed and above frame rails of the pickup truck accordingto one embodiment.

FIG. 6 is a perspective view of a tubular member for spin-welding onto across-member of the reinforcement assembly, according to one embodiment.

DETAILED DESCRIPTION

Embodiments of the present disclosure are described herein. It is to beunderstood, however, that the disclosed embodiments are merely examplesand other embodiments can take various and alternative forms. Thefigures are not necessarily to scale; some features could be exaggeratedor minimized to show details of particular components. Therefore,specific structural and functional details disclosed herein are not tobe interpreted as limiting, but merely as a representative basis forteaching one skilled in the art to variously employ the embodiments. Asthose of ordinary skill in the art will understand, various featuresillustrated and described with reference to any one of the figures canbe combined with features illustrated in one or more other figures toproduce embodiments that are not explicitly illustrated or described.The combinations of features illustrated provide representativeembodiments for typical applications. Various combinations andmodifications of the features consistent with the teachings of thisdisclosure, however, could be desired for particular applications orimplementations.

FIG. 1 illustrates a pickup truck 10 having many structural elementsmade of aluminum. The pickup truck 10 includes a cargo bed or truck bed12 that is rearward of a passenger compartment 14 of the truck. Thetruck bed 12 is shown with an open and exposed top, although otherembodiments exist in which the truck bed is covered. A tailgate 16 ishinged at its bottom to provide access to the upper surface of the truckbed 12. When opened, the tailgate 16 and the upper surface of the truckbed 12 can be coplanar to provide a flat load surface.

Many of the components of the pickup truck 10 can be made of aluminum.The truck bed 12 is no exception, and may be made of 6000-seriesaluminum. If such a material choice is made for the truck bed 12,additional reinforcement structures may be provided to aid in thestrength and rigidity of the truck bed 12. These reinforcementstructures, as will be described below, can also be made of 6000-seriesaluminum. Particular configurations of these reinforcement structuresprovide the aluminum truck 10 with strength comparable to typical trucksthat are made mostly of steel.

FIG. 2 shows the underside 20 or bottom surface of the truck bed 12. Thetruck bed includes a length L, extending along the length of the truck,and a width W. As can also be seen in FIG. 1, the truck bed can includea series of longitudinal grooves 22 to add structural rigidity. Evenwith these grooves 22, the bed can still be referred to as substantiallyflat, as the majority of the upper surface of the bed is indeed flat.

Beneath the underside 20 of the truck bed is a plurality ofreinforcement assemblies, a portion of which are shown in isolation inFIG. 3. Each of the reinforcement assemblies includes a cross-member 24extending across the grooves 22 and along the width of the truck bed 12.Each cross-member 24 includes a generally horizontal (parallel to thetruck bed) base 26. A pair of opposing sidewalls 28 extend from the base26 at relative obtuse angles (e.g., between 91-110 degrees) from thebase 26. These opposing sidewalls 28 also extend along the length of thecross-member 24, forming a channel 29 within the concave or interiorsurface of the cross-member 24. A pair of flanges 30 is spaced from andparallel to the base 26, with each flange extending from a respectivesidewall. The flanges provide engagement surfaces to engage thereinforcement assembly to the underside 20 of the truck bed.

The cross-members 24 can be made of 6000-series aluminum that isroll-formed. Roll-forming is an efficient method of manufacturing astamped component in which the shape of the component is constant andfree of any undulations or stark changes in geometry. A roll-formedcross-member 24 provides a longitudinal, one-piece supporting beam thatadequately provides support to the truck bed.

Referring to FIGS. 2-5, a plurality of spacers or reinforcement members34 are provided on the outside surface of each of the cross-members 24.The reinforcement members 34 each include a base 36 that engages arespective cross-member 24. Sidewalls 38 of the reinforcement member 34also extend from the base 36 at angles similar to that of the sidewalls28 extending from the base 26 of the cross-member. A channel is definedby the base 36 and the sidewalls 38. The base 36 and the sidewalls 38are configured to engage with and contact the base 26 and sidewalls 28of the cross-member 24.

To supplement the strength of a single-piece roll-formed cross-member24, the reinforcement member 34 can be made of 6000-series aluminum thatis extruded. In an extrusion process, aluminum in a malleable state canbe “pushed” through a formed shape, such as the shape of thereinforcement member, and cut or broken to length. When placed below thecross-member 24 and opposite from the truck bed, the reinforcementmember 34 acts as a spacer to create a clearance zone for componentsbeneath the truck bed. This eliminates the need to create localizeddents in the truck bed or the cross-members 24, enabling roll-formingdue to a constant shape (as previously described).

The base 36 of the reinforcement member 34 can be extruded and formedsuch that it is sized to provide adequate clearance for the givenvehicle package clearance conditions beneath the truck bed 12. The base36 may be thicker than the sidewalls 38 to not only aid in supportbeneath the cross-member 24 relative to the sides of the cross-member24, but also to provide for the clearance beneath the cross-member 24.The base 36 and the sidewalls 38 add strength to the cross-member 24,inhibiting crushing of the cross-member 24 under heavy loads whilemaintaining clearance between the truck bed and components beneath.

A typical pickup truck includes a pair of frame rails that are disposedbelow the truck bed 20 and run along the length L of the truck bed.Referring to FIG. 5, the cross-member 24 and the support member 34 areshown as part of a reinforcement assembly 42 between the truck bed 20and one or more frame rails 44 of the truck. Rather than a directconnection between the truck bed 12 and the frame rails 44, thereinforcement assembly 42 may provide a space between the underside 20of the truck bed 12 and the frame rails 44. In particular, the flanges30 of the cross-member 24 contact the underside of the truck bed 20,while the base 36 of the support member 24 contacts one of the framerails 44.

To secure the reinforcement assembly 42 between the truck bed 20 and theframe rails 44, a crush tube or extruded tube 46 is provided on eachsupport member 34. Each tube 46 may be spin-welded to an upper surfaceof the base 36 of the reinforcement member 34. For example, in oneembodiment, an end face 48 of the tube 46 can be spin-welded on the base36 with the length of the tube 46 extending between the sidewalls 38. Aplurality of annularly-spaced surface features 50 are provided about theouter surface of the tube 46 to facilitate the flow of aluminum duringthe spin-welding. The surface features 50 are shown as rounded ribs thatare regularly- and annularly-spaced and extend along the length of thetube 46. The surface features 50 may be any other shape capable ofproviding additional material about the outer surface of the tube tofacilitate spin-welding. In other embodiments, the surface features 50include one or more longitudinal groove formed in the outer surface ofthe tube 46. In yet other embodiments, a series of alternating groovesand ribs are formed on the outer surface.

The extruded aluminum tube 46 spin-welded to the extruded aluminumreinforcement member 34 provides additional support under the truck bed20 and maintains a spaced relationship between the truck bed 20 and thereinforcement member 34 and frame rails 44. The tube 46 acts to furtherinhibit crushing of the cross-member 24 and its supporting componentsunder heavy loads.

An exemplary method of manufacturing and assembling the reinforcementassembly 42 will now be described. A plurality of the 6000-seriesaluminum cross-members 24 are formed via roll-forming, including thebase 26, sidewalls 28 and flanges 30 described above. At least twoclearance holes 52 are punched, cut or otherwise formed in thecross-member 24 at spaced-apart locations to be later aligned with theframe rails 44 transverse to the cross-member. Reinforcement members 34having the base 36 and sidewalls 38 described above are formed viaextruding 6000-series aluminum such that the reinforcement members 34include channels. Tubes 46 with surface features 50 are also formed viaextruded 6000-series aluminum. The tube 46 can be extruded such that ahole 54 exists through the central axis of the tube 46. Each tube 46 isspin-welded to the interior surface within the channel of eachreinforcement member 34. A hole (not shown) in the reinforcement member34 may also be formed and aligned with the hold 54 of the tube 46.

Once welded, one of the tubes 46 is inserted through a clearance hole 52of one of the cross-members 24. Because of the similar shapes of thebases and sidewalls, the reinforcement member 34 can be pressed suchthat its interior surface nests with the exterior surface of thecross-member 24. This aligns the reinforcement member 34 and tube 46 ofone cross-member 24 with one of the frame rails 44. The process can berepeated to nest two reinforcement members 34 with each of thecross-members 24 at locations to be secured to the frame rails 44(explained below). Each reinforcement member 34 maintains a spacedrelationship between the cross-member 24 and the frame rail 44, whileindirectly connecting the two. A fastener (e.g., bolt, screw, etc.) canthen be driven or inserted into the truck bed 20, through the hole 54 ofthe tube 46, through the reinforcement member 34 and into the frame rail44. This secures the reinforcement assembly 42 between the truck bed 20and the frame rail 44 in a cargo bed assembly.

As mentioned above and best seen in FIG. 2, the reinforcement assembly42 includes the one roll-formed cross-member 24 with a pair of spacedapart extruded support members 34. Each of the support members 34 isaligned with one respective frame rail beneath the truck bed extendingalong the length L of the truck bed. In other words, a plurality ofsupport members 34 attached to different cross-members 24 are alignedalong a single frame rail. In the embodiment illustrated in FIG. 2,three cross-members 24 are provided, each having a pair of supportmembers 34. Half of the support members 34 are linearly aligned forattaching to one frame rail, while the other half of the support members34 are linearly aligned for attaching to another frame rail. Otherembodiments are contemplated in which more or less than the illustratednumber of cross-members and/or support members are provided.

While embodiments described above are directed to a pickup truck, itshould be understood that the structural features of the presentdisclosure can be utilized with other vehicles, for example sportsutility vehicles (SUVs), vans, etc.

While exemplary embodiments are described above, it is not intended thatthese embodiments describe all possible forms encompassed by the claims.The words used in the specification are words of description rather thanlimitation, and it is understood that various changes can be madewithout departing from the spirit and scope of the disclosure. Aspreviously described, the features of various embodiments can becombined to form further embodiments of the invention that may not beexplicitly described or illustrated. While various embodiments couldhave been described as providing advantages or being preferred overother embodiments or prior art implementations with respect to one ormore desired characteristics, those of ordinary skill in the artrecognize that one or more features or characteristics can becompromised to achieve desired overall system attributes, which dependon the specific application and implementation. These attributes caninclude, but are not limited to cost, strength, durability, life cyclecost, marketability, appearance, packaging, size, serviceability,weight, manufacturability, ease of assembly, etc. As such, embodimentsdescribed as less desirable than other embodiments or prior artimplementations with respect to one or more characteristics are notoutside the scope of the disclosure and can be desirable for particularapplications.

What is claimed is:
 1. A cargo bed assembly for a truck, the assemblycomprising: a substantially flat aluminum bed; an aluminum cross-memberhaving a base and a pair of sidewalls extending from opposing sides ofthe base, the cross-member mounted to an underside of the bed; and analuminum reinforcement member in contact with the base and at least aportion of the sidewalls, and disposed between the cross-member and aframe rail of the truck.
 2. The cargo bed assembly of claim 1, whereinthe reinforcement member is 6000-series extruded aluminum.
 3. The cargobed assembly of claim 1, wherein the cross-member is 6000-seriesroll-formed aluminum.
 4. The cargo bed assembly of claim 1, furthercomprising a second reinforcement member, wherein each reinforcementmember is aligned with and secured to separate frame rails.
 5. The cargobed assembly of claim 1, wherein the cross-member and the reinforcementmember each include a base surface, wherein the base of thereinforcement member engages the base of the cross-member and the framerail.
 6. The cargo bed assembly of claim 5, wherein the cross-memberincludes opposing sidewalls that extend generally transverse from thebase surface, and a pair of flanges that extend from the sidewalls forattaching to the underside of the bed.
 7. The cargo bed assembly ofclaim 1, wherein the reinforcement member spaces the cross-member fromthe frame rail.